In the aeronautics industry, it is known to use a spherical plain bearing for preventing two members, such as a rod and a structural part, from moving axially relatively while allowing a relative rotational movement of the members.
Such bearing generally comprises an inner ring having a truncated spherical outer surface and an outer ring having a truncated spherical inner surface in contact with the outer surface. The inner and outer rings thus have three degrees of freedom in rotation, while being firmly fixed to each other in translation.
In order to obtain a light spherical plain bearing, it is known to form the inner ring from a metal or from a metal alloy having a low density, for example titanium, titanium alloys, aluminum and aluminum alloys. However, the frictional behavior of such metals and metal alloys is not compatible with the stresses applied in operation to the inner ring by the shaft onto which is mounted the bearing.
Accordingly, the spherical plain bearing may further comprise a sleeve mounted into the bore of the inner ring and made from a material having good friction properties as described for example in EP-B1-1 431 597. The disclosed sleeve comprises, at one end, a radial shoulder axially bearing against a frontal surface of the inner ring.
With such a sleeve, the angular slewing capacity of the spherical plain bearing is limited. Besides, it is necessary to foreseen additional axial retaining means to prevent relative axial movement between the sleeve and the inner ring.